Improvement in lifting-jacks



-W. H. GREENWALT.

Improvement in Lifting-Jacks. No. 126,286, Patented April30,1872.

WITNESSES. INVEINTOR.

?, M74 ARM/L C Qzzga UNITED STATES PATENT QFFICE.

WILLIAM H. GREENWALT, OF STRIGKERSVILLE, PENNSYLVANIA.

IMPROVEMENT IN LlFTlNG-JACKS.

To all whom it may concern:

Be it known that WILLIAM H. GREENWALT, of Strickersville, in the county of Chester and State of Pennsylvania, has invented a new and valuable Improvement in Carriage-Jacks; and he does hereby declare that the following is a full, clear, and exact description of the construction and operation of the same, reference being had to the annexed drawing making a part of this specification, and to the letters and figures of reference marked thereon.

Figure 1 of the drawing is a representation of a vertical longitudinal section of my invention. Fig. 2 is a front view of the same.

This invention has relation to carriagejacks; and consists in the construction and novel arrangement of the lifting-lever, vertically-moving post, and anti-friction rollers, as hereinafter described.

Referring to the accompanying drawing, A A represent two parallel uprights, secured to a sill, B, and supporting between them the operative devices of the jack. 0 designates a vertically-movable post, constructed with the steps or offsets d to receive the carriage-axle, the depending arm d holding the anti-friction roller 01 and the vertical slots at, through which passes the pin that keeps the post G in place, and which is provided with an anti-friction roller 6. 0 represents other anti-friction rollers arranged on either side of the depending arm at, and adapted to guide the same. F

designates the lifting-lever, constructed with rounded head F eccentrically pi\ oted. The edge of said lever-head is in contact with the roller d so that when the arm of the lever is lowered the post 0 is raised. At a point furthest distant from the pivot f a concave depression, g, is made in the edge of the leverhead, into which the roller d falls when the post 0 is raised to its highest position. The object of this depression is to lock the lever and post. When the roller 01 is in the notch g the weight upon the post can have no efl'ect on the movement of the lever. To prevent wear the edge of the lever-head should be covered by a strip of metal, h.

What I claim as my invention, and desire to secure by Letters Patent, is-

1. The lever F, having the eccentric head F with notch g, in combination with the sliding post 0 having the anti-friction roller d substantially as and for the purpose specified.

2. The combination of the post 0 having the slot 01 and depending arm d with the antifriction rollers e e d and eccentric lever F, substantially as and for the purpose specified.

In testimony that I claim the above I have hereunto subscribed my name in the presence of two witnesses.

WILLIAM H. GREENWALT.

Witnesses:

GEo. H. WATSON, WM. H. SIMPERs. 

